javascript - What is gained when you .extend() an obj prototype with itself -

i looking @ code, , make sure wasn't losing mind missing obvious looks me, there nothing gained. seems wasteful usage of $.extend() perhaps can shed light on might missing inheritance.

so, have this.

_letscreatenamespace('us.somenew.obj'); //this based on s.stoyanov namespace pattern, _letscreatenamespace does. 

then seen in code, , didn't make sense me.

us.somenew.obj = function(){   // var assignments.   this.blah = $foo; }  // usage of extend escapes me. don't see need @ point here. $.extend(us.somenew.obj.prototype, {   // bunch of new methods   } 

i not see @ benefit of using $.extend() instead of following, there no extending itself.

 us.somenew.obj.prototype = {    // bunch of new methods  } 

there no 'deep' extend or anything.. looks verbose way of extending prototype no reason.

am missing something? there "forest behind tree's" methodology missing here?

$.extend copies prototype methods given without overwrite prototype object itself. instance, if have:

// inheritance us.somenew.obj.prototype = myproto;  us.somenew.obj.prototype =  {    // lost inheritance `myproto`, here } 

using $.extend prevent that. plus, won't lose default property. example, constructor:

us.somenew.obj = function () {};  us.somenew.obj.prototype = {};  var o = new us.somenew.obj();  console.log(o.constructor === us.somenew.obj) // false, in case `object` 

where:

us.somenew.obj = function () {};  $.extend(us.somenew.obj.prototype, {});  var o = new us.somenew.obj();  console.log(o.constructor === us.somenew.obj) // true